Tuesday, May 11, 2010

The Chemistry of Archaeopteryx

False color view of the Thermopolis Archaeopteryx. The image is a composite blend of scans of the elements phosphorus, silicon, sulfur, and iron. The bright colors in the wing areas show how part of the feather chemistry has been preserved. Image: K.G. Huntley/Stanford Synchrotron Radiation Lightsource

By recording how the X-rays interacted with the Thermopolis Archaeopteryx, researchers were able to identify very precisely the locations of chemical elements hidden within. From this, they created the first maps of the dinobird's chemistry, revealing half a dozen chemical elements that were actually part of the living animal itself. In almost every element studied, the researchers found significantly different concentrations in the fossil than in the rock that surrounds it, confirming that the observed elements are indeed remnants of the 'dinobird' and not merely chemicals that leached from the surrounding rock into the fossil.

The chemical maps show that portions of the feathers are not merely impressions of long-decomposed organic material—as was previously believed—but actual fossilized feathers that contain phosphorous and sulfur, elements that comprise modern bird feathers. Trace amounts of copper and zinc were also found in the 'dinobird's' bones; like birds today, the Archaeopteryx may have required these elements to stay healthy.

"We talk about the physical link between birds and dinosaurs, and now we have found a chemical link between them," said Roy Wogelius.. link